Large-scale spatial and interspecies differences in trace elements and stable isotopes in marine wild fish from Chinese waters
Highlights
► A large-scale study on trace element levels in marine wild fish from Chinese waters. ► Spatial variation found for Al, As, Cd, Cr, Fe, Ni, Pb, but not for Ag, Cu, Mo, Se and Zn. ► The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb. ► No biomagnification occurred for any of the trace elements studied in marine fish. ► No obvious health risk from the intake of trace elements through fish consumption.
Introduction
With the recent very rapid development of industry and agriculture in China, a large number of harmful substances have been discharged into the sea, resulting in coastal water pollution. These substances are often persistent and have potentials of being bioaccumulated by the marine organisms. In a most recent review of trace metal pollution in estuarine and coastal waters of China, Pan and Wang [1] concluded that industrial and domestic sewage discharges, mining, smelting, and e-wastes recycling are the important sources contributing to coastal pollution in China. Metal contamination in the coastal environments is closely associated with accelerated economic growth in the past decades. Various compartments such as sediments, water and organisms collected from the heavily industrialized areas often contained alarmingly high metal concentrations. Such elevated levels of metal contamination along China's coastal environment can increase the risk of metal exposure to humans by seafood consumption.
Fish are the major seafoods consumed by humans. FAO [2] estimated that about 75% (105.6 million tons) of worldwide fish production were directly consumed by human in 2004 alone. In the China Seas, there are a variety of marine species and outputs, but all of these marine fish species are currently under serious threats. Levels of contaminants in fish are of particular interests due to their potential risks to humans. Numerous studies have measured the trace elements levels in different species of edible fish worldwide [3], [4], [5], [6], [7]. Several earlier studies in China reported trace elements contamination in seawater, sediments, and bivalves [1], with only few focusing on marine fish [8], [9], [10].
This study represents the first large-scale investigation of multi-elemental accumulation in marine wild fish from China Seas. We targeted the analysis of twelve trace elements (Ag, Al, As, Cd, Cr, Cu, Fe, Mo, Ni, Pb, Se, and Zn) in their muscle tissues. Mercury was not specifically analyzed in this study, despite the fact that it is probably the most important in terms of human health exposure assessment. The marine wild fish were caught from seven main coastal areas from Northern to Southern parts of China. We also collected the marine wild fish from the Pearl River Estuary, the second largest estuary in China. With the establishment of many industrial developmental zones along the coastal cities, estuaries are especially vulnerable to metal pollution due to uncontrolled release of industrial effluents. The main objectives of this study were to examine whether the marine wild fish were contaminated with trace elements, and to test whether there were any spatial or interspecific variations in the coastal or estuarine environment. Health risk assessment was then conducted to evaluate whether these marine wild fish presented any potential risk to humans as a result of consumption. From a public health perspective, this study could provide consumers with better knowledge of contamination problems associated with seafood consumption. In addition, we also used the stable isotope approach (δ13C and δ15N) to estimate the relationships among concentrations of trace elements, food sources and trophic levels of fish species.
Section snippets
Sampling
Twenty-nine marine wild fish species of similar sizes were collected from eight stations along the coastal areas in China, including seven main coastal cities (Qinhuangdao, Dalian, Qingdao, Shanghai, Huilai, Zhanjiang and Haikou) and the Pearl River Estuary (Fig. 1), between April and May 2010. Each species were represented by 10–20 individuals, with a body length of approximately 10 cm. The collected samples were transferred to the laboratory and rinsed with distilled water three times. The
Geographic variation of metal concentrations
The concentrations of 12 trace elements in fish collected along the Chinese coastal waters are shown in Table 1. Differences of trace elements concentrations in different fish and from different locations are described below.
The Ag concentrations in the fish were generally very low (0.38–7.52 ng/g) among all the locations. Several species of fish had their tissue Ag concentrations lower than the limit of quantitation (LOQ) or method detection limit (MDL) (0.1 ng/L). There was no clear spatial
Geographic variance
Earlier studies largely reported trace elements concentrations in marine fish based on wet weight. Table 3 compares the trace elements concentrations in marine fish collected from different locations of the world. A wet/dry weight conversion factor of 4 can be used for easy comparison [7].
Among the 12 trace elements quantified in this study, Ag, Cu, Mo, Se, and Zn had no clear spatial differences among all the locations (from Northern to Southern parts). Several possibilities may explain such
Conclusion
Accumulation of trace elements (such as Al, As, Cd, Cr, Ni, Pb) in food is a major safety health concern worldwide. The present study involved a large scale investigation of trace elements in marine wild fish in China Seas. The data indicated that trace elements levels had geographic differences, likely due to the differences of trace elements bioaccumulation and the sources of industrial and agriculture inputs. The distribution trend revealed the current economic status of development from the
Acknowledgments
We thank the anonymous reviewers for their helpful comments. This work was supported by the CAS (Chinese Academy of Sciences)/SAFEA (State Administration of Foreign Experts Affairs) International Partnership Program for Creative Research Teams (KZCX2-YW-T001) and the Innovation Group Project of Chinese Academy of Sciences (KZCX2-YW-Q07).
References (43)
- et al.
Trace metal and organochlorine residue levels in red mullet (Mullus barbatus) from the eastern Aegean, Turkey
Water Res.
(2001) - et al.
Fish tissue quality in near-coastal areas of the Gulf of Mexico receiving point source discharges
Sci. Total Environ.
(2002) - et al.
Heavy metals in commercial fish in New Jersey
Environ. Res.
(2005) - et al.
Bioaccumulation of trace elements in pelagic fish from the Western Indian Ocean
Environ. Pollut.
(2007) - et al.
Trace elements in two marine fish cultured in fish cages in Fujian province, China
Environ. Pollut.
(2010) - et al.
Trace elements and stable isotopes (δ13C and δ15N) in shallow and deep-water organisms from the East China Sea
Environ. Pollut.
(2008) - et al.
Copper uptake kinetics and regulation in a marine fish after waterborne copper acclimation
Aquat. Toxicol.
(2009) - et al.
Determination of metals in fish species from Aegean and Mediterranean seas
Food Chem.
(2009) - et al.
Heavy metal and Pb isotopic compositions of aquatic organisms in the Pearl River Estuary, South China
Environ. Pollut.
(2005) Toxic and essential trace elemental contents in fish species from the Black Sea, Turkey
Food Chem. Toxicol.
(2009)
Trace metal content in nine species of fish from the Black and Aegean Seas, Turkey
Food Chem.
Arsenic contamination and potential health risk implications at an abandoned tungsten mine, southern China
Environ. Pollut.
Arsenic content and fractionation in the surface sediments of the Guangzhou section of the Pearl River in Southern China
J. Hazard. Mater.
Metal content determination in four fish species from the Adriatic Sea
Food Chem.
Heavy metal distribution in different fish species from the Mauritania Coast
Sci. Total Environ.
Potential human health risks from metals (Hg, Cd, and Pb) and polychlorinated biphenyls (PCBs) via seafood consumption: estimation of target hazard quotients (THQs) and toxic equivalents (TEQs)
Food Chem. Toxicol.
Concentrations of trace elements in marine fish and its risk assessment in Malaysia
Mar. Pollut. Bull.
Trace element content of Boletus tomentipes mushroom collected from Yunnan, China
Food Chem.
Health risk assessment of eight heavy metals in nine varieties of edible vegetable oils consumed in China
Food Chem. Toxicol.
Trace metal contamination in estuarine and coastal environments in China
Sci. Total Environ.
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